1. Technical Field
The present invention relates to a liquid ejecting apparatus that supplies liquid housed in a liquid housing portion via flow paths to a liquid ejecting head and a liquid supplying method for the liquid ejecting apparatus.
2. Related Art
A printer (liquid ejecting apparatus) which supplies ink (liquid) housed in an exchangeable cartridge (liquid housing portion) to a liquid ejecting head and ejects ink to a target from the liquid ejecting head to perform printing has been known (see JP-A-2004-98365).
In such a printer, even when liquid that has been housed in the cartridge is run out of, it is possible to perform printing by exchanging the cartridge with new one. However, when it is necessary to exchange cartridges during printing, printing must be interrupted. Then, there cause mottled patterns in printing matters and printing quality may be reduced.
Accordingly, a printer is proposed in which a plurality of cartridges are coupled to the liquid ejecting head, and even when ink housed in one cartridge is run out of, it is possible to supply ink from another cartridge and continue printing.
There is a type of ink such as pigment ink which causes precipitation or aggregation as time passes and causes concentration imbalance. Therefore, when such ink is supplied to the liquid ejecting head, there sometimes causes concentration imbalance in ink in a flow path which couples the liquid ejecting head to the cartridge.
That is, when a plurality of cartridges are coupled, ink flows in a flow path which couples the cartridge for supplying ink (supply liquid housing portion) and the liquid ejecting head. Therefore, concentration imbalance in ink in a flow path is not easily caused. However, since in a flow path (housing portion side flow path) corresponding to another cartridge (non-supply liquid housing portion), ink stagnates to be stopped, and concentration imbalance is easy to be caused.
Note that such a problem is not limited to a printer which supplies ink housed in the cartridge to the liquid ejecting head via a flow path. That is, such a problem is generally common to the liquid ejecting apparatus that supplies liquid housed in the liquid housing portion to the liquid ejecting head via flow paths and the liquid supplying method for the liquid ejecting apparatus.